Microstructures, Wear Behavior and Mechanical Properties of the TiC Ceramic Particulate Locally Reinforced Ni-Hard4 White Cast Iron Matrix

2016 ◽  
Vol 69 (8) ◽  
pp. 1571-1578 ◽  
Author(s):  
Vahid Javaheri ◽  
Mahyar Mohammadnezhad ◽  
Masoud Bahrami
Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 933 ◽  
Author(s):  
Juan González ◽  
Luis Borja Peral ◽  
Alfredo Zafra ◽  
Inés Fernández-Pariente

High alloy white cast irons (WCI) play an important role in many industrial fields such as mining, cement industry, or grinding due to their high hardness and wear resistance. In all these processes, white cast iron components must work under erosion and abrasion conditions. Many investigations have been carried out with the aim of improving the mechanical properties of this type of alloys. Wear resistance depends on the mechanical properties, mainly hardness. Thus, the WCI are typically heat treated in order to modify its microstructure, improving its tribological and wear behavior. The aim of this study is to propose a mechanical surface treatment, shot peening, as an alternative to global heat treatments, due to its capacity to induce phase transformation and microstructural modification, at the same time that it improves the mechanical properties of materials. Characterization of different treated samples was performed by means of microstructural characterization, X-ray diffraction analysis, SEM observation, hardness and roughness measurements, and erosion tests. The results show that shot peening treatment is able to transform residual austenite and increase hardness in the top surface layer of the material. Both effects contribute to improve the erosion wear behavior of the WCI.


1984 ◽  
Vol 34 ◽  
Author(s):  
P. L. Roy ◽  
A. K. Chakrabart ◽  
P. Banerjee

ABSTRACTMinor additions (0.05-0.2 wt.%) of sodium chloride, hexachloroethane and elemental sulphur to commercial white iron melts have been found to enhance the kinetics of first stage graphitisation during subsequent annealing of white iron samples. The optimum dose of sodium chloride and hexachloroethane addition is around 0.1%. Yield strength and ductility of annealed test bars treated with NaCl or C2Cl6 compare favourably with those of untreated test bars. Sulphur treatment causes slight deterioration in mechanical properties. Fully grown nodules in both treated and untreated samples appear porous under SEM. Possible mechanisms of acceleration of graphitisation in the treated samples have been suggested.


2021 ◽  
Vol 1016 ◽  
pp. 56-62
Author(s):  
Carlos Camurri ◽  
Jasmín Maril ◽  
Eric Romero

The aim of this work was to study the wear behavior of high-chromium white cast iron of families ASTM A-532 II (B, D) and III A, used in mining equipment, in order to establish relationships between the wear resistance, hardness and microstructure of the alloys, with the ultimate purpose of predicting their resistance to abrasion. Samples from these cast irons were subjected to mechanical wear tests by rotating drum, then their micro/macro hardness was measured and microstructure analyzed by optical and scanning electron microscopy .It was found that when the macroscopic hardness differences were significant there was a strong correlation between the hardness and the loss of mass due to abrasion-impact wear. By contrast, when the alloys had similar hardness, the wear resistance was determined by morphology, size, and the distribution and connectivity of carbides and matrix and therefore was not predictable by an only simple hardness test.


2011 ◽  
Vol 18 (11) ◽  
pp. 31-39 ◽  
Author(s):  
Havva Kazdal Zeytin ◽  
Hakan Yildirim ◽  
Banu Berme ◽  
Selim Duduoĝlu ◽  
Gürkan Kazdal ◽  
...  

2007 ◽  
Vol 26-28 ◽  
pp. 293-296 ◽  
Author(s):  
Guo Shang Zhang ◽  
Yi Min Gao ◽  
Jian Dong Xing ◽  
Shi Zhong Wei ◽  
Xi Liang Zhang

To improve the wear resistance of high chromium white cast iron under severe abrasive conditions, a composites layer was designed for wear surface, which were locally reinforced with WC particles. And the local composites were successfully fabricated by optimized centrifugal casting process. Then the interface between WC and iron matrix was analyzed with scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). And three body wear tests were carried out on a self-made rig to investigate the wear resistance of the composites. For comparison, the wear tests of high chromium white cast iron were also carried out under the same conditions. The results show that: There are no defects such as inclusion, crack, gas pore and so on in the obtained composites layer, which with a uniform thickness of 10 mm. WC particles are homogeneously distributed in the composites layer and tightly bonded with the iron matrix. The WC particles are partially dissolved in the iron matrix during centrifugal casting. The elements W, C and Fe react to form new carbides such as Fe3W3C or M23C6, which precipitate around former WC particles during subsequent solidification. So the interface between WC particles and the iron matrix is a strong metallurgical bonding. WC particles in the composites layer can effectively resist cutting by the abrasive, and then protect the matrix. The wear resistance of the composites layer is 7.23 times of that of high chromium cast iron.


Author(s):  
Julieta Kaleicheva ◽  
Krasimir Kirov ◽  
Valentin Plamenov Mishev ◽  
Zdravka Karaguiozova

The microstructure and mechanical properties of high chromium white cast iron with composition: 2,6÷3,4% C; 0,9÷1,1% Si; 0,8÷1,1% Mn; 1,0÷1,3% Mo; 12,3÷13,4% Cr, additionally doped with boron in an amount of 0,18% to 1,25% is investigated. The microstructure of six compositions of white cast irons is studied by means of an optical metallographic analysis - one without boron, and the others contain 0,18%; 0,23%; 0,59%; 0,96% and 1,25% boron. A test is performed to determine: hardness by the Rockwell method; microhardness; bending strength and impact toughness. It was found that at a boron content of 0,18%; 0,23% and 0,59%, the structure of white cast irons is subeutectic, with impact toughness in the range of 1,80÷1,52 J/cm2; with a boron content of 0,96%, the structure of white cast iron is close to the eutectic, with impact toughness 0,98 J/cm2 ; at a boron content of 1,25% the structure of white cast iron is supereutectic and the impact toughness decreases to 0,68 J/cm2. With a change in the boron content from 0,8% to 1,25%, the amount of carbide phase in the structure of white cast iron increases, which leads to an increase in hardness from 53 to 59 HRC. The highest bending strength (Rmi=660,85 MPa) was obtained in white cast irons with a boron content of 0,23%. 


2017 ◽  
Vol 26 (46) ◽  
Author(s):  
Oscar Fabián Higuera-Cobos ◽  
Jeison Bucurú-Vasco ◽  
Andrés Felipe Loaiza-Patiño ◽  
Mónica Johanna Monsalve-Arias ◽  
Dairo Hernán Mesa-Grajales

This paper studies the influence of variables such as holding temperatures and times during austempering of High Chromium White Cast Iron (HCWCI), with the following chemical composition: Cr 25 %, C 3 %, Si 0.47 %, Mn 0.74 % and Mo 1.02 %. The aim of the austempering was to modify the percentage of retained austenite and its correlation to abrasive wear resistance under different conditions.Microhardness tests, SEM-EDS and XRD were performed to determine mechanical properties, chemical composition, and type of carbides and microstructures present, respectively. The tests complied with the ASTM G-65 standard. Results showed that the best performance against abrasion was achieved for austempering at 450 ºC with holding time of 6 hours.


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